A bulb marked 12 V, 24 W operates 12 volt battery for 20 minutes. The energy consumed is:
The correct option is A $$28800 J$$ Energy ($$power\times time$$) is measured in Joules and by including time (t) in the power formulae, the energy dissipated by a component or circuit can be calculated.
Energy dissipated Q= Pt.
In the question, the time taken is given as 20 minutes, that is $$20\times 60=1200\quad seconds$$ and the power is 24 W.
Hence, the energy consumed by the bulb is $$24\quad W\times 1200\quad s=28,800\quad Joules$$.